There has been known a semiconductor device such as a power metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT) in which a gate electrode and a gate insulating film are formed on an inner wall of a trench formed in a front surface of a semiconductor substrate.
A semiconductor device is disclosed in US 2016/0013311 in which a PN junction diode is formed between two left transistors and two right transistors out of four transistors arranged in one direction.